What is the function of molecular oxygen in cellular respiration?
Correct answer: A. Oxygen is the final electron acceptor in the electron transport chain
- A. Oxygen is the final electron acceptor in the electron transport chain
- B. Oxygen breaks down glucose during glycolysis
- C. Oxygen is used to directly produce ATP in the Krebs cycle
- D. Oxygen acts as an enzyme to speed up cellular reactions
Explanation
The correct answer is A-Oxygen is the final electron acceptor in the electron transport chain. Molecular oxygen's key role in cellular respiration is to accept electrons and hydrogen ions at the end of the electron transport chain to form water. This step is vital because it maintains the flow of electrons through the chain, allowing the cell to continue generating large amounts of ATP through oxidative phosphorylation. Oxygen is not involved in glycolysis, does not directly participate in the Krebs cycle, and is not an enzyme. Without oxygen, the electron transport chain stops, and cells must rely on much less efficient anaerobic pathways for energy production.
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About Bioenergetics
Cellular respiration explains how cells release energy from glucose through glycolysis, the link reaction, Krebs cycle and electron transport chain. It includes ATP production, substrate-level and oxidative phosphorylation, aerobic versus anaerobic respiration, and the roles of mitochondria, oxygen and fermentation in energy transfer.
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